A MOF-74(Ni) derived partially oxidized Ni@C catalyst for SO2 electro-oxidation integrated with solar driven hydrogen evolution

Abstract

The SO₂ electro-oxidation reaction (SO₂OR) is a feasible tactic to alleviate SO₂ pollution and an alternative to the oxygen evolution reaction (OER) in the electro-production of H₂. However, efficient SO₂OR catalysts are still limited to Pt and Au. Here, we report an efficient partially oxidized Ni@C (po-Ni@C) SO₂OR catalyst, which exhibits better performance than the 20% Pt/C catalyst. Also, utilizing the po-Ni@C catalyst mediated SO₂OR to replace the Ti/IrO₂–Ta₂O₅ catalyzed OER can vastly alleviate the electro-consumption in the hydrogen electro-production. Furthermore, a solar to hydrogen electrolyzer was established and delivered ∼25 mA current powered by a 1 V commercial silicon solar cell. This work may provide a new strategy for the design of SO₂OR catalysts and establish waste SO₂ treatment and H₂ electro-production systems.